I want to send data to the client without having it redirect and show the data in the browser. The server is written in node.js using express.js.
It is for a login function.
I need to have it work like this since the idea of the system is to use the front-end purely as a GUI for interacting with the API.
res.send("Login failed").redirect(homepage);
I've seen framework-engine which I suppose I could use, but I would like to avoid as much additional "software" as possible. Essentially my question is: How do I send data back to the client so that it can be used in an already shown HTML page.
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A novice javascript developer here!
A have a basic question on whats the best and secured way to make HTTP calls from a front application to a backend service that needs an authentication. My application is a SPA (using Vue.js) & getting data from Java services. Java services need authentication details and return sensitive user data.
I see there are a few options and I wanted to understand a better approach amongst all 3-
Making direct HTTP calls from javascript code- Concern for using this approach is, as Javascript code can also be viewed via dev tools in browser, wont it be easier for anyone to do an inspect and view all critical authentication details hence making overall integration less secure?
Making an HTTP call using Axios via Vue framework- Seems like Axios is Promise based HTTP client for the browser that lets you easily make HTTP calls without much code overhead. but is this secure? is Javascript code loaded in the browser? Or the front end code sends the request and axios makes the request from backend server where the application is hosted?
Using Node- If front end application has unique routes configured for each API call and in my application if I have a route mapping to use request module and node js backend code to make those HTTP calls, is that going to be a robust and secure way of integration?
Please let me know your thoughts and apologies if this is a dumb question!
Not dumb at all. You're just learning.
My first question to your answer 😅 will be: is your application server-side rendered or it's sap + backend?
If it's server-side rendered then I would say it's secured since Node will be sending pages with all required data. On the dev tool, you will only see static files being loaded.
However, if it's SAP, I am not sure whether there is a way to hide whatsoever you send to the server from the dev tool. The only one thing you will need to do is to make sure you encrypt whatever is sensitive to your application.
So I have made a back-end in NodeJS but I ran into one problem, how is it possible to link my back-end to my front end html/css page and use my NodeJS functions as scripts?
In case this wasn't clear to you, your nodejs back-end runs on your server. The server's job (in a webapp) is to deliver data to the browser. It delivers HTML pages. It delivers resources referenced in those HTML pages such as scripts, images, fonts, style sheets, etc.. It can answer programmatic requests for data also.
The scripts in those web pages run inside the browser which is nearly always (except for some developer testing scenarios) running on a completely different computer on a completely different local network (only connected via some network - usually the internet).
As such, a script in the browser cannot directly reference variables that exist in the server or call functions that exist on the server. They are completely different computers.
The kinds of things you can do in order to work-around this architectural limitation are as follows:
The server can dynamically modify the web page it is sending the browser and it can insert data into that web page. That data can be in the form of already rendered HTML or it can be variables inside of script tags that your web page Javascript can then use.
The javascript in the web page can make network requests to your server asking it for data. These are often called AJAX calls. In this scenario, some Javascript in your page sends a request to the server to retrieve some data or cause some action on the server. The server receives that request, carries out the desired operation and then returns a result back to the client Javascript running in the browser. That client Javascript receives the result and can then act on it, inserting data into the page, making the browser go to a new web page, prompting the user, etc...
There are some other ways that the web page javascript can communicate with the server such as webSocket connections, but we'll put those aside for now as they are just more ways for remote communication to happen - the structure of the communication doesn't really change.
how is it possible to link my back-end to my front end html/css page and use my NodeJS functions as scripts?
You can't directly use your nodejs functions as scripts in the front-end. You can make Ajax calls to the server and ask the server to execute it's own server code on your behalf to carry out some operation or retrieve some data.
If appropriate, you can also insert scripts into the web page and run Javascript directly in the browser, but whether you can do that for your particular situation depends entirely upon what the scripts are doing. If the scripts are accessing some resource that is only available from the server (like a database or a server storage system), then you won't be able to run those types of scripts in the browser. You will have to use ajax calls to ask the server to run them for you and then retrieve the results.
I am sending a JSON with some important data to the frontend using Nodejs.
If i enter in the explorer the url of the JSON i am requesting the json data is displayed.
Also, if i firebug the website i am able to view the POST or GET requests with that important data.
I need a way of communicating with from backend to frontend but being encrypted so that nobody can never see that important data.
I am thinking of using google fusion tables (excel in the cloud) to achieve this, but i am sure there must be a simpler solution.
Regards,
I'm extremely new to node.js, and have years of experience in PHP, so my thinking about the issues below, might be tainted by my backed ways.
I'm currently using node set up with foundation CSS, and using their reveal modal windows to display most of my forms. I want to avoid re-displaying them upon submit, and instead, validate them on client side.
Basic user creation will have fields as per below:
name
email
password
password confirmation
Form my basic validation i can use require to validate the input,
input(type="text",name="user[email]",placeholder="#",required)
but I would also like the client to check if the email already exists after the user types it in, and whether the passwords are correct.
I've been reading about the validator module but from the documentation I read about it, I only understand how to validate the values after they've been posted. I've seen the express-form module as well, but It's no longer maintained, so I would rather avoid it.
Could someone point me in the right direction?
I don't have any experience with validator or express-form, and I am not sure you need them for what you are trying to achieve. Most of what you are trying to do will be client side work (e.g. jQuery Ajax calls to validate the data) That kind of client-side code should be pretty much the same regardless of whether you use a Node.js backend or a PHP backend.
Injecting the initial JavaScript in your Jade page should be pretty straightforward once you figure out the proper syntax to include JavaScript in a Jade page. The wiring of DOM events on the page to make Ajax calls (onClick, onTextChanged, et cetera) will be conceptually the same as if you were writing a plain HTML page.
In your Node.js server side you'll need a route to handle the request to validate if an e-mail address already exists and that code very likely will return JSON that you will use in your client side form to display the results of the validation to the user. But that should also be very similar to what you would have done with a PHP backend.
I have a small Node.js HTTP server that does requests to a mongo database (with the mongoose module).
What I want to do is query the database, store it in a variable (array) and send it to the client.
Because ideally, when the user clicks on one of the buttons on the html page, the JavaScript will pick-up the event and change the appearance of the website by showing calculations based on data that is stored in the database.
The only way I could come with was just "transferring" the database content to the client browser but if anyone can come with another solution that would be fine too !
So basically my question is :
How can I pass a variable from the Node.js server to the client browser when serving a page ?
Thank you in advance !
If you will be doing more than a couple of these types of transfers, I recommend looking into Socket.IO.
It's a layer that provides quick and easy communication between Node.js servers and web front-ends, by abstracting web sockets when available, and falling back to other transports (such as JSON-P or Flash) when it's not available. Basically, you would call io.emit('something', {yourdata: here}), and it is easily received on the other end. All of the serialization is done for you.
http://socket.io/
Give their demo a shot to see how it works.